The Neuropathology Core (Core D) functions as an integral component of each of the Projects providing histopathologic services and Neuropathologic expertise. The Core PI (David R Hinton MD) and Core Colnvestigator (Roscoe Atkinson MD) are both board certified Neuropathologists with extensive experience in the evaluation of murine central nervous system (CNS) tissues. Support provided to each of the projects includes: 1) participation in development of experimental design for animal experiments; 2) tissue processing; 3) tissue sectioning (frozen sections and paraffin-embedded sections); 4) histochemical and immunohistochemical staining of tissue sections; 5) neuropathologic interpretation of tissue sections (by light microscopy or confocal microscopy); 6) documentation ofthe pathology by digital microscopy; 7) preparation of figures for manuscripts; 8) storage and retrieval of stained slides for each of the projects. Expert preparation and neuropathologic evaluation of tissues ensures high quality, unbiased assessment of CNS tissues for pathologic alterations including inflammation, demyelination and viral infection.